Mikhail Gorbachev would like the United States to lift the restrictions on US-Soviet trade imposed by the so-called Jackson-Vanik amendment. He pointedly raised the issue with President Reagan at the Moscow summit. But as American relations with Moscow improve across a range of issues, conservatives are marshaling their forces to forestall any administration effort to waive the restrictions.

The Jackson-Vanik amendment, which was attached to the Trade Reform Act of 1974, denies most-favored-nation (MFN) status and other trade preferences to communist countries unless they permit free emigration.

A House-Senate conference will soon take up an amendment to the defense authorization act that goes even further than Jackson-Vanik. Sponsored by Sen. James McClure (R) of Idaho and adopted by the Senate last month, the amendment would withhold MFN status from the Soviet Union until there was ``substantially complete compliance'' with the Helsinki accords, above all on human rights.

``The West paid a high price for the Soviets' promises on human rights at Helsinki by formally recognizing their annexations of territory and the postwar division of Europe,'' Senator McClure said yesterday at a conference on the Soviet Union. ``We should insist that they hold up their end of the agreement.''

While Senate observers expect the McClure amendment to be dropped as extraneous to the defense bill, the issue is again stirring debate within the US government and among Jewish organizations. In light of growing emigration of Jews, Armenians, and others from the Soviet Union under Mr. Gorbachev's reform policies, the Reagan administration is considering a waiver of the Jackson-Vanik restrictions to encourage trade expansion. American Jewish leaders also appear open to such a move.

The American business community, for its part, views Jackson-Vanik as a hindrance to trade. And while not many business organizations are calling for repeal of the amendment, viewing that as politically unrealistic, they support a waiver of the restrictions to improve the political atmospherics for doing business with Moscow.

``Economically and commercially, granting MFN to the Soviets wouldn't make that much difference,'' says Donald Hasfurther, a US Chamber of Commerce official. ``But the major impact of waiving Jackson-Vanik would be political and that would help ... trade.''

Without MFN tariff treatment, which most nations enjoy, the Soviet Union is disadvantaged in the American market. And while there are not many high-quality Soviet manufactured products that attract customers in the US, it is politically galling to the Soviets that the USSR is not accorded equal-trade treatment and reciprocity.

Congressional observers expect the issue to gather interest over the next few months, especially if Jewish emigration from the USSR continues to grow. Some 8,000 Jews emigrated last year and the rate so far this year is higher.

``The whole Jackson-Vanik issue has become ripe again, but it hasn't been ventilated enough yet for a change of policy,'' a Senate source says. ``We need a few more months of good emigration numbers. Once it's clear that Gorbachev is firmly in the saddle and the emigration numbers continue, there'll be a good opportunity to modify Jackson-Vanik. A waiver could be an interim step.''

On the House side, too, there are efforts to tighten restrictions on business with the USSR. Reps. Jack Kemp (R) of New York and Toby Roth (R) of Wisconsin have introduced a bill requiring private banks to make public their loans to East-bloc countries and give the president authority to ban such deals if he deems them not in the national interest.

Congressman Kemp and other House conservatives also support the McClure amendment.

But the administration opposes the measure as counterproductive because, by requiring substantial compliance on human rights as a whole, it would place demands on the Soviets that they could not satisfy.

``It would add a new condition to MFN which would make it virtually impossible for the Soviets to meet,'' a Commerce Department spokesman says.

``The McClure bill puts more weight on MFN than it can bear,'' says a State Department official. ``It could jeopardize the efforts to accelerate the upward trend in emigration.''

Emigration of Soviet Jews has increased to about 900 a month since mid '87, say US officials. This is viewed as an encouraging sign, although officials stress there is still a long way to go.